Social media network homophily among political candidates in multilevel settings

Figures & data

Figure 1. Networks of candidates by parliament.

Figure 2. Networks of candidates by language.

Figure 3. Networks of candidates by parliament/language.

Figure 4. Networks of candidates by party.

Table 1. Attribute assortativity measures.

Attribute	Assortativity
Parliament	0.205
Language	0.883
Parliament/Language	0.283
Party	0.881

Table 2. Average weighted degree measures for party, language, parliament and parliament/language groups.

Parliament		Language^a		Parliament/Language		Party
EU Parliament	12.00	French Dutch	30.05 31.25	EU Parliament: Dutch-speaking EU Parliament: French-speaking	14.04 5.08	CD&V cdH MR PS	21.73 24.68 45.67 39.78
Belgian House of Representatives	17.35			Belgian House of Representatives: Dutch-speaking	17.81	Ecolo Listes Destexhe	16.39 16.17
				Belgian House of Representatives: French-speaking	23.95	UF DéFI PP	2.00 15.40 31.29
Parliament of the Brussels-Capital Region	16.65			Parliament of the Brussels-Capital Region: Dutch-speaking	9.00	Open Vld Sp.a Groen	20.06 20.82 37.90
Flemish Parliament Walloon Parliament Parliament of the German-Speaking Community	12.75 6.60 Not connected			Parliament of the Brussels-Capital Region: French-speaking	11.22	N-VA Vlaams Belang PVDA/PTB	34.64 37.73 50.64

^aGerman has been excluded because of the small number of candidates (N = 2).

Table A1. List of parties.

Name	Description
French-speaking parties
MR (Mouvement Réformateur)	French-speaking liberal party
PS (Parti Socialiste)	French-speaking social democrats
cdH (Centre démocrate humaniste)	French-speaking Christian democrats
Ecolo	French-speaking green party
Listes Destexhe	French-speaking liberal-conservative party
Défi (Démocrate Fédéraliste Indépendant)	French-speaking social-liberal, regionalist party
UF (Union des Francophones)	French-speaking regionalist party
Dutch-speaking parties
Open VLD (Open Vlaamse Liberalen en Democraten)	Dutch speaking liberal party
SP.A (Socialistische Party Anders) –	Dutch-speaking social democrats
	Vooruit since March 2021
CD&V (Christen-Democratisch en Vlaams)	Dutch-speaking Christian democrats
Groen	Dutch-speaking green party
N-VA (Nieuw-Vlaamse Alliantie)	Dutch-speaking Flemish Nationalist party
Vlaams Belang	Dutch-speaking populist radical right party
German-speaking parties
PFF (Partei für Freiheit und Fortschritt)	German-speaking liberal party
SP (Sozialistische Partei)	German-speaking social democrats
CSP (Christlich-Soziale Partei)	German-speaking Christian democrats
ProDG (Pro Deutschsprachige Gemeinschaft)	German-speaking Christian democratic, regionalist party
Vivant	German-speaking social-liberal party
State-wide party
PVDA/PTB (Partij van de Arbeid/Parti du Travail de Belgique)	State-wide radical left party

Table A2. Total number of candidates and retweets within each party, language group, parliament, and parliament/language.

Party	# Cand	# RT	Language	# Cand	# RT	Parliament	# Cand	# RT	Parliament/language	# Cand	# RT
CD&V	86	1411	Dutch	535	12 115	EU Parliament	68	2629	EU Parliament: Dutch-speaking	43	1502
cdH	55	853	French	353	7946				EU Parliament: French-speaking	23	1125
MR	70	2570	German	2	4				EU Parliament: German-Speaking	2	2
PS Ecolo Listes Destexhe UF DéFI PP Open Vld sp.a Groen N-VA Vlaams Belang PVDA/PTB	70 59 22 2 36 13 93 59 82 130 51 61	1754 2243 224 23 472 325 1427 1068 2243 2943 1519 2475				Belgian House of Representatives Parliament of the Brussels-Capital Region Flemish Parliament Walloon Parliament Parliament of the German-Speaking Community	308 179 248 87 2	7113 4262 4949 1110 2	Belgian House of Representatives: Dutch-speaking Belgian House of Representatives: French-speaking Parliament of the Brussels-Capital Region: Dutch-speaking Parliament of the Brussels-Capital Region: French-speaking	204 133 40 110	4757 3412 907 2299

Notes: The table includes candidates who retweeted other candidates (890) and their number of retweets by party, language, parliament and parliament/language. The total number of retweets is 20 065. The table does not include candidates who were retweeted but did not retweet tweets of other candidates themselves (N = 45), as we obviously have no data on their retweets as they did not retweet another candidate.